JP2804876B2 - Communication method for network system including multiplex system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates, in a network system including a multiplex system device relates to a communication technology for transmitting data.

[0002]

2. Description of the Related Art In recent years, techniques for decentralization of computer systems and the like have been developed due to higher performance and lower cost of information processing systems such as computers and further development of network technology.

As an example of a conventional data communication method in a network, a communication method using a communication frame called a “MAC frame” specified in, for example, IEEE 802.3 is well known.

[0004] The "MAC frame" includes a head port number portion having a source port number, a broadcast address at the time of broadcast transmission, and a destination port address at the time of point-to-point communication, and a data portion. doing.

In such a communication method, the communication frame configured as described above is used for transmission as a communication protocol.

As a method of transmitting data to a master side of a multiplex system (usually configured with a master system and a slave system), for example, as shown in FIG.
A transmission control device 405 is provided between the duplex device 402 and the network 408, and the transmission control device
There is a method of determining which device in the duplex system is the main system and performing a relay process for transmitting data.

Also, in a network device having a configuration in which a transmitting device on the data transmitting side and a multiplex system on the data receiving side are connected via a common bus line, the network device is connected to the bus line in advance. the shared memory provided in advance by the information one is either a primary system side of the multi-system device to store, the transmitting-side apparatus, when the data transmission, with reference to the master-slave information in the shared memory, communication There is a known way to do this.

[0008] Further, there is known a method of notifying a communication partner device of information indicating that such switching has occurred when switching of an operating system occurs in a multiplex system.

[0009]

According to the conventional communication method, in the network configuration shown in FIG. 3, the main system side of the dual system device 302 including the device 301, the device 307 and the device 308. Consider the transmission of various data to this device.

In this case, data transmission is performed according to the following procedure.

First, the apparatus 301 sends a “transmission request” to the apparatuses 307 and 308 constituting the duplex apparatus 302 to confirm which is the main apparatus. Send

The device 30 that has received the "transmission request"
7 or the device 308 transmits to the device 301 information indicating that the device is the main device.

Thus, the device 301 recognizes the main device and transmits data to the main device. For this reason, in data transmission between the apparatus 301 and the main apparatus constituting the duplex apparatus, it is necessary to perform communication processing at least three times (data transmission to the main system is performed at the third time). there were.

[0014] Such interaction, than was done every time of data transmission, increased load on the network, problems such as an increase in the processing time of the data transmission arising.

In order to solve such a problem, the following means have been proposed.

First, between the device 403 and the device 404 constituting the dual system as shown in FIG.
5, a means for determining the master-slave information in the duplex system by the transmission control device.

However, in such a configuration, a transmission control device must be provided in response to the increase in the number of multiplexing devices, resulting in an increase in cost and the like. In addition, when the communication function of the transmission control device is stopped due to a failure or the like, there is a problem that data transmission cannot be performed even when the multiplex device is operating.

Second, a transmitting apparatus for transmitting data,
If a dual system is connected via a common transmission line and a shared memory or the like is provided, and mutual data transmission is to be managed based on information stored in the shared memory, the device It is necessary to manage all of them. For example, there is a problem that a transmission line becomes long-haul or the like, and there is a problem that it is not practical to construct a wide area system having a plurality of networks.

Thirdly, the communication partner from the multiplexing system device, the method of notifying the state change (such that switching between the main system and the slave has occurred) or the like, the communication partner of all hand, should know beforehand If the system that is the communication partner is out of order and a notification is leaked, there is a problem in that data transmission from the device having the leaked notification to the main system cannot be performed thereafter.

Therefore, in the present invention, in consideration of the above-mentioned problems, even if it is not necessary to recognize which of the devices constituting the dual system is the main system, the other system can be used for the dual system. It is an object of the present invention to provide a communication method capable of performing data communication with a main system side device.

[0021]

The following means are conceivable to solve the above-mentioned problems.

A data transmission method between devices in a network system in which at least one device is a duplex device connected via communication means, wherein a port number is previously defined in the device. Further, when the device is a dual device, in addition to the port numbers being predetermined for the two devices constituting the device, a representative port number is also predetermined for the dual device itself. In addition,
Each of the devices stores state information indicating whether each of the two devices constituting each of the duplex devices connected to the network system is a master system or a slave system. When the port number is a data communication address, the representative port number is converted into the port number of the main device based on the status information, and the data is transmitted.

In this case, at the time of system start-up, each of the devices inquires of the two devices constituting each of the duplex devices connected to the network system at the time of system startup. It is preferable to check for the presence and store it.

It is preferable that the status information is updated at a predetermined time (for example, periodically, at the time of failure, etc.). In addition,
The present invention can be applied to a multiplex system of two or more systems.

[0025]

According to the communication method of the present invention, a device constituting a multiplex system can be handled as a single virtual device without considering whether it is a master system or a slave system.

That is, the actual data transmission is performed after confirming the port number of the device to which the data is to be transmitted, that is, determining the port number of the corresponding device in the duplex system as the communication destination. It is not necessary to recognize the configuration of each device in the multiplex system.

Of course, it is also possible to directly transmit data to each device by using the port number assigned to each of the plurality of devices as the communication address of the corresponding device.

Further, according to the processing in the apparatus on the data transmitting side according to the present invention, referring to the storage contents in which the status of the communication partner is stored in advance, the main system side in the multiplex apparatus is referred to. Transmit data to the device.

Therefore, a process for recognizing the state of each device constituting the multiplex system every time data is transmitted becomes unnecessary.

Further, if a process for confirming the state of the multiplex system from the transmitting apparatus is performed once at the time of a data communication error which occurs when the state of the multiplex system as a communication destination changes, the multiplex system can be thereafter performed. There is no need to perform a process of checking the status of each device constituting the device each time data is transmitted.

[0031]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows a network configuration example for explaining one embodiment of the present invention.

Reference numerals 302 and 303 denote devices 307, respectively.
And a device 308, a device 309, and a device 310.

The device 307 and the device 308 or the device 309 and the device 310 can be arbitrarily switched between the master system and the slave system, respectively.
It has the function of transmitting data to each duplex device.

[0035] Of course, device 301 may be one of the devices of the dual system devices.

Each of the networks, loops 304 and 3
05 is connected via a coupling device 306 such as a router, and data transmission is reliably performed.

As the communication address, a port number assigned to each device in advance is used. In a duplex system, a logically representative port number is assigned in advance and used as a communication address. That is, in the dual system device, a port number is assigned to the dual system device itself, in addition to the main or sub system devices.
FIG. 1 shows a functional block diagram of the transmission device.

In FIG. 1, a computer A0 is connected via a network N0 . As the network N0 ,
For example, it can be realized by a LAN (local area network) using an optical fiber as a communication means.

The computer A0 includes a communication control unit 110 , a state management table 120 , and a user program 130 . These are realized by, for example, a main storage unit in a computer and a program stored therein.

The user program is, for example, various application programs, and has a function of requesting a data transmission process to a communication control unit.

When the communication partner is a duplex system, the communication control unit 110 determines whether each of the devices constituting the duplex system is the master system or the slave system. A management function 111 ; a data transmission processing function 112 for transmitting data to the corresponding device; Detection function 1 for erasing the information
13 . Although not shown, data transmission is performed according to a predetermined communication protocol.

When the communication partner device is a duplex device, the status management table 120 indicates the status of each device constituting the duplex device (information such as whether the device is a master system or a slave system). The contents are referred to when the communication partner state management function 111 is activated, and are stored in the failure detection function.
It is updated when 113 is started.

Similarly, FIG. 2 shows a receiving apparatus (dual system apparatus).
FIG.

In FIG. 2, computers A1 and A2 are connected via a network N1 . The network can be realized, for example, by a LAN (local area network) using an optical fiber as a communication means.

The computer A1 includes a communication control unit 210 , a state management table 220 , and a user program 230 . These are realized by, for example, a main storage unit in a computer and a program stored therein. The computer A2 is realized by the same configuration as the computer A1.

The user program is, for example, various application programs, and has a function of receiving data sent from a transmission source.

Although not shown, the communication control unit 210
A data reception processing function 212 for receiving data in accordance with a predetermined communication protocol, an own device status acquisition function 214 for determining whether the own device is a master system or a slave system, and a communication partner (data transmission It has a status notification function 215 for transmitting data obtained by adding the status of the own device to the source) and a failure detection function 213 for detecting a failure during communication.

The status management table 220 is a means for storing the status of whether the own device is the master system or the slave system, and the contents are updated and referenced by the activation of the own device status acquisition function 214. . FIG. 11 illustrates how information is exchanged between the transmitting and receiving apparatuses according to the first embodiment of the present invention.

First, consider a case where data is transmitted from the device 301 to the duplex device 303.

Referring to FIG. 6, a processing procedure up to data transmission by the transmitting apparatus will be described.

First, in step 601, the device type of the communication partner is identified based on the communication address of the specified device. If the communication destination address is other than the representative address of the duplex system, do not change the specified address.
Proceed to step 608.

Next, in step 602, if the communication destination address is representative of a dual system device (3
03 is specified), and the contents of the state management table 120 that manages the information on the master / slave state of the communication partner stored in the own device in advance are referred to.

It is checked whether or not information on the corresponding device is held in the state management table 120. If the information is held, the process proceeds to step 607.

In step 603, a "POINT TO POINT line" (a line constituted by a so-called point-to-point link is hereinafter referred to) is opened for inquiring of both systems. In this embodiment,
As a protocol (communication protocol) when using the “POINT TO POINT line”, TCP / IP (Tra
nsmission Control Protocol
1 / Internet Protocol).

This protocol is a transmission control protocol having high reliability and providing one-to-one communication. A configuration having a transmission error check function, an error retransmission function, and the like may be employed.

In the "TCP / IP", it is necessary to establish a virtual communication path (connection) between the transmitting and receiving devices before performing data communication.

Both systems (301-309 and 301-309)
Opening a “POINTTO POINT line” with respect to 310) means establishing a connection between the devices 301 and 309 and between the devices 301 and 310.

In step 604, an information frame for inquiring about the device status (status indicating whether it is a master system or a slave system) is transmitted to both systems using the opened line in step 603. I do. This corresponds to 1101 in FIG.

At step 605, response information to which the status of each device is given from both systems is received. However, since the live / dead state of the communication partner (whether or not it is out of order) is not known,
Since the timing at which the response information is sent cannot be grasped, in this step, processing such that the response information may be sent at any time, for example, until the response information of the device is received,
Processing such as weighting is included. This corresponds to 1102 in FIG. In step 606, based on the response information obtained in step 605, the information is stored in the state management table of the master / slave state of the communication partner existing in the own apparatus.

In step 607, the contents of the master / slave state management table 120 are referred to, and the representative communication address is converted into the communication address of the corresponding master device.

In step 608, a "POINT TOPOINT line" is opened based on the communication address, and data transmission processing is performed. This corresponds to 1103 in FIG.

FIG. 5A shows “POINT TOP”.
An image diagram of data transmission using the “OINT line” is shown.

Now, referring to FIG. 7, the device (3
09, 310, etc.) in the receiving apparatus. In step 701, "POINT TO
Open a "POINT line" and request the establishment of a connection. This corresponds to 1101 in FIG.

Next, in step 702, inquiry information from the transmitting device is received. Next, step 7
In step 03, a process of acquiring the status of the own device (whether it is a master or a slave) is performed with reference to the status management table 220 in the own device. At this time, processing such as checking the state of the duplex system (master or slave) specified by the transmitting apparatus may be performed.

In step 704, a process for sending response data to the transmission inquiry destination is performed. This is shown in FIG.
Corresponds to 1102.

After the transmission of the data, the connection is released, or a process of waiting until the actual data information is received is performed.

As described above, thereafter, data transmission to the main system side of the duplex system can be efficiently performed by one transmission unless an abnormality such as system switching occurs in the duplex system. .

The processing when a communication error occurs will be described below.

FIG. 8 shows the processing procedure.

First, in step 801, a process for detecting the occurrence of a user data information frame transmission error is performed. This step includes a process corresponding to a change in the state of the device that can be detected in advance, such as a prior notification by a system monitoring function such as a stop of the communication partner device.

Next, in step 802, processing for identifying a device in which a communication error has occurred is performed. At this time, a process is performed to determine whether the device in which the communication error has occurred is a dual device.

In step 803, the corresponding status management table of the duplex device in which the communication error has occurred is deleted, and the initial status is restored.

In step 804, notification processing such as alarm output is performed according to the content of the abnormality.

Thereafter, data transmission to the corresponding duplex device can be performed again in the same procedure as the procedure from step 601 described above.

Next, as a second embodiment according to the present invention, a process for transmitting data from the device 301 to the duplex device 302 belonging to the same network will be described as an example.

Although data transmission can be performed by the means described in the first embodiment, in this embodiment, data transmission can be performed even if the transmitting device does not know the partner device in advance. Is described.

FIG. 12 illustrates how information is exchanged between the transmitting and receiving apparatuses according to the second embodiment of the present invention.

FIG. 9 shows a processing procedure of the transmitting apparatus.

First, in step 901, a multicast line is opened.

In this embodiment, as a protocol when using a multicast line, "UDP / IP" (Use
r Datagram Protocol / Inter
net Protocol).

This protocol generally has low reliability because there are procedures that are not prepared in transmission control (for example, there is no transmission error check function, no error retransmission function, etc.).

However, since no connection is established between the transmitting and receiving apparatuses, it is possible to transmit an information frame to a plurality of apparatuses by one transmission. In contrast, "TCP / IP" requires multiple transmissions.

Next, in step 902, the inquiry information is multicast-transmitted to a plurality of devices using the line opened in step 901.

FIG. 5B shows an image diagram of multicast transmission.

The information frame transmitted from the device 301 is simultaneously sent to the devices 307 and 308 and also to other devices belonging to the same network. This corresponds to 1201 in FIG.

Next, in step 903, the receiving device that has received the data in step 902 makes a request for establishing a connection that the data has been received.
In addition to notifying the transmitting device, the status of the own device is acquired and the transmitting device is notified of the status. Generally, a side that requests connection establishment is called a “client”, and a side that accepts a connection connection request is called a “server”.

That is, the receiving side becomes a client and opens a “POINT TO POINT line”.

Thus, unlike the first embodiment, the transmitting device can know the statuses of a plurality of duplex devices at a time, and it is not necessary to know the status of the partner device before transmitting. , The system expandability is improved.

In this processing, the transmitting apparatus can obtain a specific address of the communication destination, and can perform processing based on the address. In FIG.
This processing corresponds to step 605, and corresponds to the data response indicated by 1202 in FIG.

Next, in step 904, the obtained information is stored in the state management table 120 based on the response information. That is, a process corresponding to step 606 shown in FIG. 6 is performed. Next, in step 905, the same processing as steps 607 to 608 in FIG. 6 is performed. That is, data is transmitted to the corresponding device. In FIG. 12, this corresponds to 1203.

Thereafter, the transmission of data from the dual system to the main system can be performed only once unless the state is changed due to system switching or the like in the dual system.

Next, FIG. 10 shows a processing flow on the receiving side.

First, in step 1001, step 9
A multicast line is opened in response to the process of No. 01.

Next, in step 1002, the multicast data (inquiry information) sent by the processing of step 902 is received. This corresponds to 1201 in FIG.

Next, in step 1003, based on the data of the inquiry information received in the processing of step 1002, the state of the own apparatus is referred to the state management table 220, and a connection is established with the transmitting apparatus. Make a request. This corresponds to 1202 in FIG.

Next, in step 1004, the same processing as the processing in step 704 is performed. This is shown in FIG.
Corresponds to 1203.

In the case of an abnormality, steps 801 to 8
04 can be dealt with by performing the same processing.

As described above, after that, data transmission to the main system side of the duplex system is performed by referring to the state management table 120 and transmitting the data to the corresponding system by the “POINT TO POINT line” unless a communication error occurs. I can do it.

However, in the second embodiment, since inquiries to both systems are made via the multicast line, the target range is limited to the same network, and the first embodiment is not reliable in terms of reliability.
Is inferior to the example of (1).

In each of the embodiments, the case where the device 306 is constituted by, for example, a router, and it is not necessary to be aware that the network connection device exists as a relay device has been described. When it is configured with a gateway or the like and it is necessary to be aware of the existence as a relay device, the transmitting device 301 stores the existence of the relay device 306 in the state management table 120 , and the device 306 What is necessary is just to perform the same processing as that performed at the time of data transmission from the transmission device to the duplex device.
Here, the operation according to the present embodiment described above and the operation according to the above-described conventional technique will be compared.

As described in the prior art, when a transmission control device or the like is provided between the duplex system on the receiving side and the network, the transmission control device must once perform the relay process. Therefore, if the transmission control device stops, data cannot be transmitted.

Also, the transmission control device is periodically
It is necessary to notify the status information of the device (information as to whether the device is a master system or a slave system) from the duplex system.

Further, in the method in which the multiplex apparatus informs itself of the state of the own apparatus, when the state cannot be notified, it is inevitable that information is transmitted to the wrong apparatus.

On the other hand, according to the present embodiment, since the transmitting apparatus checks the status of the duplex apparatus by itself and then performs transmission,
The transmission can be performed to the target main apparatus without going through the transmission apparatus for relay. Further, there is no need to periodically notify the status from the duplex system, and the communication load can be reduced. Of course, in normal communication, data can be transmitted to the target main apparatus in one communication, and the load on the network can be reduced.

Lastly, the present embodiment has been described by taking a duplex system as an example. However, a multiplex system in which a multiplex system is constituted by one main system such as a triple system and a plurality of standby systems. It goes without saying that the same can be applied to.

[0106]

As described above, according to the present invention, it is possible to communicate from another device to the main device of the multiplex system without recognizing the multiplex configuration of the multiplex system. A communication method can be provided.

[Brief description of the drawings]

FIG. 1 is an example of functional blocks in a transmission device when the present invention is implemented.

FIG. 2 is an example of a functional block in a transmission device when the present invention is implemented.

FIG. 3 is a configuration of an entire system for explaining an embodiment of the present invention.

FIG. 4 is a configuration diagram for explaining one embodiment of a conventional technique.

FIG. 5: Multicast, POINT TO POIN
FIG. 4 is an explanatory diagram of T transmission.

FIG. 6 is a flowchart showing a processing procedure on the transmission side in one embodiment (first embodiment) of the present invention.

FIG. 7 is a flowchart showing a processing procedure on the receiving side in one embodiment (first embodiment) of the present invention.

FIG. 8 is a flowchart showing a processing procedure when a communication error occurs in one embodiment of the present invention.

FIG. 9 is a flowchart showing a processing procedure on the transmission side in one embodiment (second embodiment) of the present invention.

FIG. 10 is a flowchart showing a processing procedure on the receiving side in one embodiment (second embodiment) of the present invention.

FIG. 11 is an explanatory diagram of exchange of an information frame between a transmitting / receiving apparatus in one embodiment (first embodiment) of the present invention.

FIG. 12 is an explanatory diagram of exchange of information frames between transmitting and receiving apparatuses in one embodiment (second embodiment) of the present invention.

[Explanation of symbols]

301: device, 302: duplex device, 303: duplex device, 304: loop, 305: loop, 306: router, etc.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06F 13/00 G06F 11/20 G06F 15/16

Claims (5)

(57) [Claims] At least one device comprises a plurality of devices.
A method for transmitting data between devices in a network system in which a plurality of devices that are multiple systems of a duplex system or more are connected via communication means, wherein the device has a port number determined in advance, wherein when apparatus is the multiplex system device constituting the device
In addition to predetermining the port number to each of the plurality of devices, multi against heavy-based apparatus itself is determined in advance a designated port number previously, also each apparatus, each multiplex is connected to a network system Each of a plurality of devices constituting the system device stores status information indicating whether the device is a master system or a slave system, and when transmitting a data, a representative port number is used as a data communication address. the representative port number is converted to the port number of the main system unit, wherein the transmitting data, a communication method of a network system including a multiplex system device based. 2. A method according to claim 1, wherein the state information, at the time of start-up of network system, each device queries to a plurality apparatuses constituting each multiplex system devices connected to the network system, any of a plurality devices it is checked whether the main system, and wherein the storing, the communication method of a network system including a multiplex system device. 3. The method of claim 2, the state information, data
And updates when a time data transmission error occurs, a communication method of a network system including a multiplex system device. 4. The method of claim 2, constituting the multiplex system device
In response to the master-slave states of a plurality devices, should be stored, when there is a change in the state information indicating whether the slave or the main system <br/>, and wherein updating the state information to, the communication method of a network system including a multiplex system device. 5. The at least one device comprises a plurality of devices.
A method for transmitting data between devices in a network system in which a plurality of devices that are multiple systems of a duplex system or more are connected via communication means, wherein the device has a port number determined in advance, wherein when apparatus is the multiplex system device constituting the device
In addition to predetermining the port number to each of the plurality of devices, multi against heavy-based apparatus itself is determined in advance a designated port number previously, when transmitting data from one device to another device, the port number and the at least one data communication address of the designated port number, characterized by transmitting the data as a transmission destination the data communication address, the communication method of a network system including a multiplex system device.